The present invention relates to a printhead capping arrangement for a printer.
More particularly, though not exclusively, the invention relates to a printhead capping arrangement for an A4pagewidth drop on demand printhead capable of printing up to 1600 dpi photographic quality at up to 160 pages per minute.
The overall design of a printer in which the arrangement can be utilized revolves around the use of replaceable printhead modules in an array approximately 8 inches (20 cm) long. An advantage of such a system is the ability to easily remove and replace any defective modules in a printhead array. This would eliminate having to scrap an entire printhead if only one chip is defective.
A printhead module in such a printer can be comprised of a xe2x80x9cMemjetxe2x80x9d chip, being a chip having mounted thereon a vast number of thermo-actuators in micro-mechanics and micro-electromechanical systems (MEMS). Such actuators might be those as disclosed in U.S. Pat. No. 6,044,646 to the present applicant, however, there might be other MEMS print chips.
The printhead, being the environment within which the printhead capping arrangement of the present invention is to be situated, might typically have six ink chambers and be capable of printing four color process (CMYK) as well as infra-red ink and fixative.
Each printhead module receives ink via a distribution molding that transfers the ink. Typically, ten modules butt together to form a complete eight inch printhead assembly suitable for printing A4paper without the need for scanning movement of the printhead across the paper width.
The printheads themselves are modular, so complete eight inch printhead arrays can be configured to form printheads of arbitrary width.
Additionally, a second printhead assembly can be mounted on the opposite side of a paper feed path to enable double-sided high speed printing.
It is an object of the present invention to provide an arrangement for reducing blockage of print nozzles during non-use of a printer.
It is another object of the present invention to provide an arrangement for reducing nozzle blockage during non-use, suitable for the pagewidth printhead assembly as broadly described herein.
It is another object of the present invention to provide an arrangement for reducing nozzle blockage for a printhead assembly on which there is mounted a plurality of print chips, each comprising a plurality of MEMS printing devices.
The present invention provides an inkjet printer, including a plurality of print nozzles for selectively ejecting drops of ink towards a print medium passing said nozzles, a space located between said nozzles and said print medium so that ink drops ejected from the nozzles pass through said space, including means for maintaining a closed atmosphere in said space at a surface of said nozzles when said printer is in a non-printing operational mode.
Preferably, the space is formed between the nozzles and a nozzle guard, the nozzle guard having a plurality of apertures aligned with the nozzles so that ink drops ejected from the nozzles pass through the apertures to be deposited on the paper or other print medium.
Preferably, the nozzles are arranged in an array extending across at least an A4pagewidth, the nozzles preferably comprising MEMS devices. Preferably, the nozzles are arranged on a plurality of print modules of the printhead each with a respective nozzle guard and space.
Preferably, air valve means shuts off air supply to the spaces when the printer is in a non-printing operational mode.
Preferably, said means for maintaining a closed atmosphere includes capping means sealing against said printhead, being moved into a capping position when said printer is in said non-printing mode.
Preferably also, the capping member is located on a rotatable platen member of the printer, and includes a seal member contacting said printhead in a locus surrounding said nozzle guard apertures.
As used herein, the term xe2x80x9cinkxe2x80x9d is intended to mean any fluid which flows through the printhead to be delivered to a sheet. The fluid may be one of many different coloured inks, infra-red ink, a fixative or the like.